DRAW

Figure 7.3.1 shows the interface of MSTEP. The method of defining tools is similar to method described in Quick-Setup. The Sheet part is the final part geometry and is required as input for MSTEP calculation.  The tools marked with blue color are optional input tools.

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Figure 7.3.1  The Analysis GUI for MSTEP

NOTE: Red indicates that the sheet is not defined. The user must define it to complete the job. Blue indicates that the bead is not defined. The user may define it as an option. Green indicates that the flat binder is defined.

The Import Results option is used to import the MSTEP calculation result into the current database.

 

BLANK MESH: Import the flat blank mesh to the current database.

BINDER MESH: Import the blank mesh generated on the surface binder.

FEATURE LINE: Import the feature line (boundary) on the blank surface.

KEEP INPUT FILE: Keep input file in the current working directory.

AUTO SAVE: Automatically save the current database file.

AUTO ASSIGN: Automatically assigns tools and sheet with common names such as blank holder, pad, etc.

CONSTRAINT: Define constraints for the blank. Please refer to Preprocess / Boundary Condition / Constraints for definition of constraint set.

ADVANCED: Allow the user to edit default parameters related to MESEP setting illustrated in Figure 7.3.2.

ACCURATE: This function allows the user to perform MSTEP on blank with the accurate finite element inverse approach (one-step method). If the user selects this option, the Force and Control Parameter options will be enabled for the user to define parameters such as Binder hold, Pad hold, Convergence and boundary constraint.

FAST: This function allows the user to perform MSTEP on part with elastic method. If the user selects this option, the Force and Control Parameter will not be enabled.

In the MSTEP Setting dialog box, the user can choose one of the following Analysis Method: Accurate and Fast. In accurate analysis, both plasticity and elastic deformation of blank are considered, also in additional to all other boundary conditions such as friction and drawbead. In fast analysis, the elastic deformation is considered. The result obtained using Accurate method is much better than Fast method for formability cases where large blank deformation takes place. Of course, the solving time of Accurate method is longer than the Fast method.

FORCE

Binder Hold: Define amount of blankholder force. The default blankholder force is 20000 Newton. User can switch the unit of force from Newton to Ton.

Pad Hold: Define amount of pad force. The default pad force is 20000 Newton.

CONTROL PARAMETER

Max. Iteration Steps: Define the Max. iteration steps during calculation. If calculation does not convergence after reaching the max. iteration steps, an error message is printed in the *.out file to inform the user. The default max. iteration steps is 200.

Disp. Convergence: Define the displacement convergence for calculation. The default displacement convergence is 0.001.

Friction: Define the friction between the blank and tools. The default friction is 0.125. User can change the value according to the real scenario.

 

HELP: Provide useful tips for stamping simulation using MSTEP.

RESTRAINT CONDITION: Allow the user to adjust the restraint condition applied on boundary. Free: no restraint; Low: 20%; Medium: 40%; Strong: 70%; User-defined: allow the user to define the force. 

SUBMIT JOB: Allow the user to submit the current job to the MSTEP solver.

EXIT: Allow the user to exit the MSTEP interface with submitting the simulation.

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Figure 7.3.2  MSTEP Setting